1. Field of the Invention
The present invention relates to a body-insertable apparatus, such as a swallowable capsule endoscope, which is insertable inside a subject and generates a transmission carrier wave when transmitting image information by radio from inside the subject.
2. Description of the Related Art
In a field of microscope, some capsule endoscopes come to be equipped with an imaging function and a radio function in recent years. The capsule endoscope is swallowed by a patient, i.e., a subject, for an observation (examination), travels inside organs (body cavities) such as a stomach and small intestine of the subject following peristaltic movements, and is naturally discharged from a living body of the subject (human body). During an observation period, i.e., a time period after the swallowing up to the discharging, the capsule endoscope sequentially images inside the subject using the imaging function thereof.
During the observation period, i.e., while the capsule endoscope travels inside the organs, image data obtained inside the body cavity by the capsule endoscope is sequentially transmitted by the radio function, e.g., by radio transmission, to an external device arranged outside the subject, and stored in a memory of the external device. When the patient carries the external device having such radio function and memory function, the patient can freely move without inconvenience after swallowing the capsule endoscope until discharging the same. When the observation by the endoscope is completed, a doctor or a nurse can display the image inside the body cavity on a display unit such as a monitor based on the image data stored in the memory of the external device and make diagnosis.
One type of the above-described capsule endoscope is described in Japanese Patent Laid-Open No. 2002-345743, for example. The swallowable capsule endoscope of Patent Document 1 incorporates a battery for power supply. An LED generates an illumination light by electricity supplied from the battery. The illumination light is directed to and reflected by a region inside the subject. An imaging element picks up the reflected light, i.e., a reflected image, and obtains image information. Thus obtained image information is transmitted by radio by a transmitting circuit.